Service Calculation

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buggaboo14

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I need some help calculating a service for a tanning salon.I've never really had to get this indepth before.It is a 1500 sq.ft. building, it has 5 tanning beds,which are 1-60amp,1-40amp,3-30amp,all which are 240 volts,I also have 2-20amp,and 1-40amp circuits for heating and a/c,220 volt.There are 20 convience outlets,and a 20amp/120 volt furnace circuit.I need help on what size service to install.Needs to be a 120/240 3-wire service,no 277/480 volt loads are required.
 
Re: Service Calculation

How's about you take a shot at performing a service calculation per Article 220, and tell us your results? We can tell you if you are on the right track or if you are missing something.
 
Re: Service Calculation

I am going to take a stab at some of this one. for general lighting loads check table 220.12 and take 1500sf and multiply by 3 for 4500va. multiply by 3 if this building would be listed under barber shop and beauty salon.
under 220.14(I) recepticle outlets would be 20 times 180va = 3600va.
your fixed electric space heating 2-20a 240v ocpd would be under 220.51 where it says to be calculated at 100% of the load. assume load is 80% of 20a ocpd =16a times 240v =3840va times 2 for 2 ocpd's= 7680va for heating.
220.80 lists air conditioning for dwelling unit but not for commercial property. need help here.
also unsure what to calculate tanning beds under.
hopefully this helped somewhat.
 
Re: Service Calculation

Originally posted by krae21:

220.80 lists air conditioning for dwelling unit but not for commercial property. need help here.
Click to expand...
220.60 Noncoincident Loads.
Where it is unlikely that two or more noncoincident loads will be in use simultaneously, it shall be permissible to use only the largest load(s) that will be used at one time for calculating the total load of a feeder or service.

try again
 
Re: Service Calculation

ok so for the 40amp 240volt a.c. unit he would take 80% of its rating making it 32amps unless nameplate gives exact F.L.A. but what about the taning beds? How would you calculate them. They may all be running at once sometimes but they are non-continuous loads.
 
Re: Service Calculation

AC @ 9600 240 X 40 This is what is given so this is what we use. We don?t want to start taking percentages and do another percentage to them again later.

The tanning beds are Inductive Lighting Loads so
220.18 (B) Inductive Lighting Loads. For circuits supplying lighting units that have ballasts, transformers, or autotransformers, the calculated load shall be based on the total ampere ratings of such units and not on the total watts of the lamps.

But don?t give up

keep trying

[ October 18, 2005, 08:55 PM: Message edited by: jwelectric ]
 
Re: Service Calculation

ok so assuming total load for everything he has 3600va for recepticles, 4500va for lighting, 9600va for a.c., 9600va for heating( two d.p. 20amp ocpd) 2400va for furnace (120v times 20a),14,400va for 60amp taning bed(240v times 60a),9600va for 40amp taning bed(240v times 40amp),21,600va for the three 30amp taning beds(240volt times 30amps times 3)
3600+4500+9600+9600+2400+14,400+9600+21,600=
75,300VA/240 VOLT = 313.75 amp service?
 
Re: Service Calculation

I would first do the continuous and then add the noncontinuous loads together.

What we do know from the original post is that the shop is 1500 square feet. This would equate to 1500 X 3 X 125% for the lighting. 5625va 220.12, definition of continuous in 100

Twenty receptacles @ 180 each would be 3600 The demand factor of 220.44 will not apply.


This gives us 9225va to this point. I see no way of going any future with out the nameplate ratings on the appliances.

The original post does not separate the heat from the AC. He only says that two twenty amp and one forty amp supplies them. Just what feeds what? Is this two window AC units and one furnace or is it two baseboard heaters and one outside AC unit?

As to the tanning beds, I have never seen a tanning bed that required a 60 amp circuit. I am not saying that there is not one, just I have never seen one.

At any rate there is not enough clear information to do a calculation. Charlie asked him to give it a try and he hasn?t.
 
Re: Service Calculation

Ok,Sorry it took me so long to return. Anyway,I have the actual amp ratings for these ,THE 60A actually draws 45A at 220V,so it would actually draw 41.25A at 240V,which gives me 9900VA,the 40A would draw 26A at 240V which gives me 6240VA,2-30A which draw 21A apiece at 240V which gives me a total of 10120VA between the two,and the other 30A draws 16A at 240V which is 3740VA. I totaled all my loads and this is what I came up with, 4500VAx125%=5625 continuos lighting load 3600VAx100%=3600 receps
9600VAx100%=9600 A/C
9900 bed
6240 bed
5060 bed
5060 bed
3740 bed
48825 total
48825/240V=203.4A
Could someone check this for me,not sure if this is right.

[ October 21, 2005, 08:59 AM: Message edited by: buggaboo14 ]
 
Re: Service Calculation

Most of the tanning salons I have been around have show windows 200va/ft. You will also need a sign circuit of 1200va per circuit needed ( one for sure )if accessible to pedestrians. You want o add those in
 
Re: Service Calculation

you need to check the load of all the tanning beds that will be installed,because some of the new tanning beds require a 150 amp circuit.
 
Re: Service Calculation

Originally posted by hess:
you need to check the load of all the tanning beds that will be installed,because some of the new tanning beds require a 150 amp circuit.
Click to expand...
150 amps? Can you see it from outer space? I think you will get a little more than a tan in that bed. :eek:
 
Re: Service Calculation

Ok, so I have to add a sign circuit which is 1200VA.The show window is 8.5ft, so I take 8.5ftx200vA=1700VA, and add these into my final calculations?
 
Re: Service Calculation

buggaboo,
you might want to consider some provision for a hotwater(appliance) in calculation also.. ;)
 
Re: Service Calculation

Originally posted by buggaboo14:
Why the appliance circuit?
Click to expand...
Well, I'm not refering to 220.53(dwelling units)but rather Art.422 Appliances (hot water heater)

As you are working this calculation in steps,and it might be determined in your thread your equipment could be gas,(I don't know)..But surely this commercial establishment, will have bathroom(s) for the patrons.

(the hot on the left thingy)

The Hot water heater (if electric)and probably not of significant size.But will be needed to be included in your calculation, of this commecial tennet space.

gas or electric?
 
Re: Service Calculation

Originally posted by buggaboo14:
it has 5 tanning beds,which are 1-60amp,1-40amp,3-30amp,all which are 240 volts,
Click to expand...
hello buggaboo,

Before we go any further,I just need to clairify a little info.The above posting,first in thread.

We also have a second posting on the beds,of a differant value(s).(posting of Oct.20,11:00pm.)

My confusion brother.
refering to 422.60(A)Nameplate Marking
and-
*220.14(a)Specific Appliances or Loads:
An outlet for a specific appliance or other loads not covered in 200.14(B) through (L) shall be calculated based on the ampere rating of the appliance or load served.

Clarification:
*You have two differant posting brother,please provide the highest marked value on those factory appliance nameplate(s)for the rated voltage.

*I just want to be sure..(not in trying to give you a hard time)


*Intersted in the "highest value" marked on name plate of these Appliance (beds).
 
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